In the Yoga Sutras of Patanjali, the mind is described as experiencing five types of mental modifications or vrittis: Pramana, Viparyaya, Vikalpa, Nidra, Smrtayah. Understanding these helps in attaining clarity and control over the mind.Pramana refers to correct knowledge gained through perception, inference, and reliable testimony. Viparyaya is incorrect knowledge or illusion, where one perceives reality wrongly. Vikalpa denotes imagination or fantasy, where the mind forms ideas without a real object. Nidra represents the mental state of deep sleep, where there is an absence of mental content but still a form of vritti. Lastly, Smrtayah stands for memory, where past experiences are recalled. visit here - https://www.yogkulam.org/blog/yoga-sutra-1-6-pramana-viparyaya-vikalpa-nidra-smrtayah